1995 Dodge Neon electrical problems

There's hundreds of electrical connections. If you're playing with the negative battery cable, I assume you're referring to the battery connections. Do you have a test light or digital voltmeter? Start by measuring battery voltage. Turn the head lights on to be sure there's some current trying to leave the battery. That will make testing more accurate.

If you have good voltage at the battery, move the negative probe to the body and check again, then move the positive probe to the next thing down the line following the smaller positive wire, and check again. Keep moving the probes down the line until the voltage disappears. That will be the point of the bad connection.